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Biomedical subjects

Y Tabata

Publications and source records attributed to Y Tabata.

At least 145 records · Page 8Linked to original sources
PubMed1993

Serum erythropoietin measurements by a one-step sandwich enzyme linked immunosorbent assay in patients with hepatocellular carcinoma and liver cirrhosis.

Erythrocytosis is occasionally observed in patients with hepatocellular carcinoma (HCC). The pathogenesis of the phenomenon remains uncertain. It has been speculated that tumors produce erythropoietin (Epo), and several studies on the Epo in tumor tissues have been reported. Using a sensitive enzyme linked immunosorbent assay, we measured the serum Epo concentration in 92 HCC patients and 30 liver cirrhosis (LC) patients. The levels of Epo in normal subjects, HCC patients and LC patients were 10.5 +/- 4.1 (mean +/- SD, mU/ml), 55.6 +/- 218.0 and 18.4 +/- 19.4, respectively. Some patients with high Epo values had low levels of hemoglobin (Hb), and a scatter-gram of the two parameters was similar to that in iron deficiency anemia. In patients whose Hb levels were more than 12 g/dl, we found Epo levels of 15.0 +/- 8.8 (mean +/- SD mU/ml) and 10.3 +/- 7.7 in HCC and LC, respectively. Epo values in HCC were significantly higher than those of normal subjects (P < 0.001) and LC patients (P < 0.05), and 18.2% (10/55) had concentrations above the upper limit of the normal range. The increase was not, however, a marked one. In conclusion, as the incidence of erythrocytosis was low (2.2%) in HCC patients, the high Epo values in some patients could be related to the abnormal production of Epo by HCC.

Carcinoma, Hepatocellular↗
PubMed1993

[Evaluation of a one step sandwich enzymeimmunoassay for serum erythropoietin--serum erythropoietin values in polycythemia vera and related hematological disorders].

We evaluated a newly developed enzymeimmunoassay for serum erythropoietin (Epo) and investigated relationship between Epo levels and hematological disorders. This method has several advantages including simplicity, high sensitivity, good precision. Moreover, the procedure requires only about 2.5 hours. Samples from 134 healthy subjects showed a normal logarithmic distribution, and its normal range was 4.5 approximately 21.3 mU/ml. The levels of Epo in normal subjects and various hematological disorders were as follows: 10.5 +/- 4.1 (mean +/- SD mU/ml) in normal subjects, 2.2 +/- 1.7 in polycythemia vera (PV), 6.1 +/- 3.1 in essential thrombocythemia, 17.8 +/- 27.3 in chronic myelogeneous leukemia, 3.6 +/- 1.8 in stress erythrocytosis, 39.4 and 14.1 in two cases of primary myelofibrosis, 1289 +/- 4798 in iron deficiency anemia and 6564 +/- 10870 in aplastic anemia. In patients with PV, serum Epo were low and did not correlate with hemoglobin concentration. However, inverse correlation was found between changes of Epo levels and hemoglobin levels in most patients. In cases in which PV progressed into myelofibrosis, anemia developed and Epo levels increased accordingly. These results suggest that the method is thought to be useful and reliable for the diagnosis and monitoring of PV and related hematological disorders.

Erythropoietin↗
PubMed1992

Benign acute myositis associated with rotavirus gastroenteritis.

Acute myositis developed concomitantly with gastroenteritis in a 2-year-old girl. She had temporary pain and swelling of the calf muscles and transient marked elevation of serum creatine kinase values. Rotavirus antigen was detected in stool by latex agglutination, and there was seroconversion of complement-fixation antibody to rotavirus.

Acute Disease↗
PubMed1991

Effects of recombinant alpha-interferon-gelatin conjugate on in vivo murine tumor cell growth.

A recombinant human alpha-interferon A/D (IFN), also known to be effective in mice, was conjugated to gelatin with a water-soluble carbodiimide. The IFN-gelatin conjugate was much more efficient than free IFN in activating mouse peritoneal macrophages (Mø) in an in vitro experiment to inhibit the growth of IFN-resistant subline cells (RR1) of murine fibrosarcoma. A single i.p. injection of the conjugate administered to normal mice was also more effective than one of free IFN in activating peritoneal Mø and natural killer cells in peritoneal exudate cell and spleen cell populations. In the investigation on body distribution of the IFN-gelatin conjugate, an enhanced affinity to Mø as well as a prolonged retention were observed in comparison with free IFN. An injection of the IFN-gelatin conjugate i.p. was more effective than one of free IFN in suppressing the in vivo growth of not only IFN-sensitive SS2 cells but also RR1 cells in the peritoneal cavity of mice, although RR1 cells were only susceptible to the indirect effect of IFN via host cells, in contrast to SS2 cells. In addition to an increased recruitment of Mø to the peritoneal cavity in RR1-bearing mice receiving i.p. injection of the IFN-gelatin conjugate, these Mø were activated to inhibit the in vitro growth of RR1 cells. These results indicate that the IFN-gelatin conjugate is a promising antitumor agent that is much more effective than free IFN. The dose of IFN in the conjugate required for exerting the antitumor effects is much lower than that of free IFN, which leads to a reduction of adverse effects of IFN.

Animals↗
PubMed1991

Depression of liver-specific gene expression in regenerating rat liver: a putative cause for liver dysfunction after hepatectomy.

We carried out studies on the expression of liver-specific genes during regeneration of the liver and searched for changes in the expression of oncogenes and housekeeping genes. Albumin and ornithine transcarbamylase genes were the liver-specific genes examined by Northern blot analysis, using total RNAs isolated from residual livers of Sprague-Dawley rats subjected to a 68% partial hepatectomy. The mRNA levels of both genes began to decrease 8 hr after hepatectomy, both reaching the lowest levels at 24 hr, and then recovered to some extent at 48 hr. In contrast, these levels in the housekeeping and growth-related genes were augmented during this period. This would suggest that there is a selective expression of growth-related and housekeeping genes, in preference to liver-specific genes during liver regeneration. The expression of these genes in the regenerating liver was simulated in primary cultured hepatocytes during the dedifferentiation processes. It would appear that the first step in regeneration of the residual liver is dedifferentiation, in which the depression of liver-specific genes may be linked to liver dysfunction following hepatectomy.

Animals↗
PubMed1991

[Virological evaluation of mumps meningitis following vaccination against mumps].

1) We report 5 cases of aseptic meningitis following vaccination against mumps. Of the 5 cases, 4 cases were diagnosed as mumps meningitis. 2 cases received monovalent mumps vaccine and the other 2 MMR vaccine. They consisted of 2 boys and 2 girls, aged 2 years and 2 months to 4 years and 5 months. The period between vaccination and symptoms ranged from 15 days to 20 days (mean 18 days). Cerebrospinal fluid of the cases contained 507 to 2688 cells/mm3. Eruption was observed in the 2 cases who received MMR vaccine, while parotid swelling was not seen in any case. 2) In all 4 cases, IgM antibody to mumps virus in the cerebrospinal fluid was detected by the ELISA or EIA methods. Causative organism of the fifth case was obscure. 3) PCR (Polymerase Chain Reaction) tests revealed that mumps virus isolated from 2 cases were of vaccine strain origin. 4) To evaluate the frequency of mumps meningitis following vaccination, it seems important to investigate carefully the number of children who received the vaccine and to exclude the cases of aseptic meningitis caused by other agents. On the other hand, cases of young infants tend to be overlooked because of atypical signs.

Child, Preschool↗
PubMed1991

Clinical experience of double filtration plasmapheresis for drug refractory neurological diseases.

The effect of therapeutic double filtration plasmapheresis (DFPP) was clinically investigated for drug refractory neurological disorders. DFPP therapy was performed 181 times for 10 patients who were treated with medical therapy of steroid or immunosuppressive drugs without any improvement of their symptoms. After the induction of DFPP therapy the neuromuscular disturbances were soon ameliorated in 9 cases of them. After DFPP, serum levels of IgG, IgA or IgM were decreased as follows: IgG 0.53 +/- 0.16; IgA 0.60 +/- 0.11; IgM 0.59 +/- 0.09 (M +/- SD). After the DFPP therapy there was no relapse in improved 9 cases. But we could not regard the immunologic markers as the index of efficacy of DFPP. Because serum levels of IgG, IgA or IgM showed a tendency to decrease by using drugs, when we didn't observe any improvement of symptoms. These results suggest that DFPP is a beneficial therapy for neurological diseases who had no effect with drug therapy, however, serum concentrations of the immunologic markers were not necessarily correlated to the severity.

Adolescent↗
PubMed1991

Assortment of posthepatectomy hyperbilirubinemia by the occurring time with reference to indication of plasma exchange.

This study was undertaken to assort the group of posthepatectomy hyperbilirubinemia by occurring time for helping elucidate its indication of plasma exchange (PE). PE was carried out for 14 cases among 198 hepatectomized patients. The 14 cases were classified for 3 groups due to the period between operation and PE. 1: Early type (less than 2 weeks), 2:Intermediate type (2 less than-less than 8 weeks), 3: Late type (greater than 8 weeks). The results were as follows. Number (liver cirrhosis (LC)) [table: see text]. The effect was expected for the early groups since PE would remove overload against the regenerating residual liver. However, there were no survival cases among the early group or LC group. These results suggest that PE may be effective for the slowly increasing hyperbilirubinemia in not cirrhotic patients and that the state of hyperbilirubinemia is the terminal stage for LC patients even under the particular situation such as posthepatectomy.

Hepatectomy↗
PubMed1990

In vitro toxicity test of 2-cyanoacrylate polymers by cell culture method.

The inhibition of Swiss 3T3 cell growth by the microspheres prepared from various 2-cyanoacrylate polymers was investigated to assess their cell toxicity. Poly(ethoxy-ethyl 2-cyanoacrylate) and poly(methyl 2-cyanoacrylate) microspheres inhibited cell growth in a smaller amount than poly-(isobutyl 2-cyanoacrylate) and poly (ethyl 2-cyanoacrylate) microspheres. The extent of cell growth inhibition by the microspheres decreased with the increasing molecular weight, regardless of the kind of polymers used. Every kind of the microspheres was degraded releasing formaldehyde in the culture medium. The cell growth inhibition by the medium containing the microspheres was observed within 24 h for poly(ethoxyethyl 2-cyanoacrylate) and poly(methyl 2-cyanoacrylate). The extent of inhibition was in a linear proportion with the amount of formaldehyde released. It is concluded that the cell toxicity of 2-cyanoacrylate polymers is attributed to formaldehyde released upon polymer degradation.

Animals↗
PubMed1990

Macrophage activation for antitumour function by muramyl dipeptide-protein conjugates.

A muramyl dipeptide (MDP) has been conjugated directly with various proteins by means of a water-soluble carbodiimide. The enhancement of the antitumour activity of mouse peritoneal macrophages by the MDP-protein conjugates has been investigated to assess the ability of the proteins for targeting MDP to the macrophages. These were activated to inhibit the in-vitro growth of tumour cells much more effectively, when immunoglobulin (IgG), fibronectin (FN), and gelatin conjugates were used than when MDP was used alone. The minimum amount of MDP in both the MDP-gelatin and the MDP-IgG conjugates necessary for macrophage activation was approximately 2000 times lower than the amount of free MDP needed. The macrophages activated by the conjugates exhibited growth inhibitory activity against phenotypically diverse tumour cells. The activity induced by the MDP-gelatin conjugate was higher than that of the MDP-IgG conjugate over the range of MDP concentrations, regardless of the isoelectric point of the gelatin used. When MDP was conjugated with bovine serum albumin (BSA), the antitumour activity of macrophages was reduced as the amount of BSA conjugated increased. With both free MDP and MDP-protein conjugates, the macrophages were more strongly activated, the longer they were pretreated. However, less pretreatment time was needed to potentiate macrophage activation by the MDP-gelatin conjugate than by free MDP. Also, the macrophages pretreated with the MDP-gelatin conjugate could maintain their activated state for longer than those pretreated with free MDP. It is concluded that gelatin is an effective carrier protein for the targeting MDP to macrophages, resulting in their activation.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1990

Drug delivery systems for antitumor activation of macrophages.

Macrophages, one of the immunologically competent cells centrally contributing to host defense mechanisms, can be stimulated by a variety of immunomodulatory agents to exert antitumor activity. However, many problems, such as serious side effects attributed to the high-dosage regimens of the drugs, should be addressed for successful tumor immunotherapy using immunomodulatory agents. Thus, it is essential to develop carrier systems that use much lower doses of the drugs. This article reviews the carrier systems of drugs for effective immunopotentiation, especially macrophage activation of antitumor function. Since research in this field has just started, few investigations, including ours, have been reported.

Adjuvants, Immunologic↗
PubMed1990

[Curability of multidisciplinary treatment including combined hyperthermia, radiotherapy and chemotherapy].

Reported are the results in 311 patients who received a multidisciplinary treatment for their cancers, said treatment combining hyperthermia, radiotherapy, and chemtherapy. Of his number, 266 patients were in the advance stage of their disease while another 42 still had localized cancers. According to the criteria of Koyama and Saitoh for evaluating solid tumors that had received chemotherapy, of 298 evaluable patients, 64 showed a complete response (CR), 94 showed a partial response (PR), 89 showed no change (NC), and 57 showed a progressive disease (PD), for an overall response of 53.0% (158 cases). A multidisciplinary treatment combining radiotherapy and hyperthermochemotherapy was used for cases involving localized tumors of the vulva, the skin, the thyroid gland, the prostate gland, the uterus, the rectum, the soft tissue bone, and the ovary, though our treatment regimen could not be continued in cases of tumors involving the stomach, the esophagus, the lung, the mediastinum, the liver, and the pancreas. Our data has shown that a high overall rate of curability was achieved in cases involving the stomach, the bladder, the blood, the skin, the head, and neck, and the esophagus.

Adult↗
PubMed1989

Elevation of c-myc transcript level in human liver during surgical resection of hepatocellular carcinoma: possible cause for underestimation of c-myc gene activation in the tumor.

It has been a matter of controversy as to whether c-myc gene expression is activated in human hepatocellular carcinoma (HCC). We observed that the c-myc mRNA level in HCC was similar to that of the adjacent non-cancerous portion, as determined in freshly obtained specimens after a partial liver resection. However, the c-myc transcript was at a low level in non-cancerous tissue which was biopsied prior to surgery, whereas it was still at a high level in HCC obtained without performing hepatectomy. These results suggest that the high transcript level observed in the non-cancerous tissue from the excised liver relates to liver resection itself, and that the c-myc gene expression is enhanced in the HCC.

Blotting, Northern↗
PubMed1989

Expression of c-myc oncogene in colorectal polyps as a biological marker for monitoring malignant potential.

The expression of oncogenes (c-myc, c-fos, c-Ki-ras, c-Ha-ras, and p53) was examined by Northern blot analysis using freshly isolated human colorectal and gastric cancers and noncancerous portions as the controls. Remarkably high levels of c-myc expression were found in colorectal cancers (eight of 11), but not in gastric cancers. High levels of c-myc expression were also detected in colorectal polyps and in metastatic liver tumors. In colorectal polyps, the transcript levels significantly correlated with the histologic malignancy and the size. In contrast, neither c-fos nor c-Ki-ras was overexpressed in colorectal and gastric cancers, and transcripts of c-Ha-ras and p53 were not evident in any tissue examined. In light of these observations the c-myc expression may be specifically associated with the evolution of colorectal cancer as well as progression and maintenance stages, hence may prove to be a useful marker to evaluate the malignant potential of colorectal polyps.

Adenocarcinoma↗